The present invention relates to methods of and to apparatus for making rod-shaped articles of the tobacco processing industry. More particularly, the invention relates to improvements in methods of and in apparatus for making rod-shaped articles (such as plain or filter cigarettes, cigars, cigarillos or the like and hereinafter referred to as cigarettes for short) of the type wherein the so-called filler (i.e., the rod-shaped body which is surrounded by a tubular wrapper of cigarette paper or the like) contains at least two different materials, e.g., two different types of shredded and/or otherwise comminuted tobacco leaves.
It is known to produce cigarettes with fillers wherein a centrally located longitudinally extending portion (hereinafter called core for short) is made of a first material and is surrounded by an elongated tubular portion (hereinafter called tube for short). The filler is draped into a continuous web of cigarette paper or other suitable wrapping material, and the resulting continuous cigarette rod it severed by a cutoff at desired intervals to yield a series or file of successive cigarettes of unit length or multiple unit length. Cigarettes of unit length constitute plain cigarettes which can be admitted into a packing machine. On the other hand, cigarettes of multiple unit length (and, in certain instances also cigarettes of unit length) are or can be admitted into a so-called tipping machine wherein the cigarettes are assembled with filter rod sections to yield filter cigarettes.
Heretofore known proposals to make rod-like fillers of the type wherein a core of a first smokable material is surrounded by a tube of a different second smokable material include the utilization of a cigarette rod maker which turns out a continuous core and advances it lengthwise along a path extending through a station wherein a second maker confines successive increments of the core in successive increments of the tube. The resulting composite filler is advanced through a mechanism which drapes a continuous web of cigarette paper around the tube, and the thus obtained continuous cigarette rod is caused to advance into the range of the aforementioned cutoff which is operated to sever the leader of the advancing cigarette rod at desired intervals to convert the rod into a file of plain cigarettes of unit length or multiple unit length.
The core can constitute an elongated empty cylindrical body or a cylindrical body which is filled with comminuted tobacco. For example, the cylindrical body can be made of a higher-quality tobacco and can be filled with tobacco of a lower quality (or vice versa).
French patent No. 998 556 discloses the making of so-called coaxial cigarettes wherein the core of the filler consists of lower-quality tobacco and is embedded in a tube consisting of or containing tobacco of a higher quality.
German patent No. 36 02 846 C2 (corresponding to U.S. Pat. No. 4,727,888) discloses the making of a composite cigarette rod wherein the core consists of a standard cigarette rod (in which a rod-like filler of tobacco is confined in a tubular envelope of cigarette paper); the core is confined in a tubular body of tobacco which, in turn, is confined in a second tubular envelope of cigarette paper or the like. The particulate material of the core and/or of the tubular body can be natural tobacco, reconstituted tobacco and/or artificial tobacco.
German patent No. 37 43 597 C1 (corresponding to U.S. Pat. No. 4,874,004) discloses a coaxial cigarette wherein the tobacco-containing (smokable) part is similar to that disclosed in German patent No. 36 02 846 C2, and which further comprises an inner filter mouthpiece aligned with one end of the core and an outer filter mouthpiece disposed at one end of the tubular tobacco-containing component and surrounding the inner mouthpiece.
German patent No. 20 15 387 C2 (corresponding to U.S. Pat. No. 3,987,804) proposes to place a cigarette rod onto a first layer of tobacco particles, to provide a second layer of tobacco particles which overlies the cigarette rod and the marginal portions of the first layer at both sides of the cigarette rod, and to thereupon drape the two layers and the cigarette rod between them into an outer envelope to form a composite cigarette rod which is ready to be severed at intervals to yield coaxial cigarettes.
A drawback of heretofore known so-called coaxial cigarettes is that they are likely to lose tobacco shreds or other forms of comminuted tobacco at their tobacco-containing ends. To the best of the inventors"" knowledge and belief, the coaxial cigarettes lack the feature which is known in connection with the making of cigarettes having a simple rod-like filler of natural, artificial and/or reconstituted tobacco, namely to reinforce (such as densify) the tobacco-containing ends of the fillers and to thus prevent the escape of tobacco particles.
An object of the invention is to provide a method of making high-quality rod-shaped articles, such as plain or filter cigarettes, cigarillos, cigars or the like, wherein rod-shaped fillers consisting of two or more different materials are confined in tubular envelopes of cigarette paper or the like.
Another object of the invention is to provide a method which renders it possible to densify the ends of fillers in rod-shaped smokers"" products wherein each filler consists of or contains two or more different smokable and/or other materials.
A further object of the invention is to provide a method of densifying the ends of fillers in plain or filter cigarettes in a novel and improved way.
An additional object of the invention is to provide a novel and improved mode of monitoring the density and/or other parameters of composite fillers which are utilized for the making of rod-shaped smokers"" products.
Still another object of the invention is to provide a novel and improved method of preventing or at least reducing the likelihood of escape of particulate material from the ends of cigarettes, cigars, cigarillos and/or other rod-shaped articles of the tobacco processing industry of the type wherein the filler consists of or contains two or more smokable or tobacco smoke filtering materials.
A further object of the invention is to provide a novel and improved apparatus for the practice of the above outlined method.
Another object of the invention is to provide the apparatus with novel and improved means for densifying the ends of fillers in cigarettes or analogous rod-shaped smokers"" products of the type wherein the fillers contain two or more different types of smokable or tobacco smoke filtering material.
An additional object of the invention is to provide an apparatus which can be readily, such as automatically, adjusted when the quality of rod-shaped smokers"" products which are produced therein, departs from a desired or prescribed quality.
Still another object of the invention is to provide the above outlined apparatus with novel and improved means for generating, processing and/or otherwise utilizing signals which denote the characteristics of the ingredients of rod-shaped fillers which contain different types of smokable and/or tobacco smoke filtering materials to be confined in the wrappers of cigarettes, cigars, cigarillos and/or other rod-shaped smokers"" products.
A further object of the invention is to provide the improved apparatus with novel and improved means for reducing the number of rejects, to enhance the quality of fillers of cigarettes or the like, and to reduce the likelihood of escape of particulate material at the ends of plain or filter cigarettes or analogous rod-shaped smokers"" products wherein the fillers contain two or more different types of smokable and/or smoke filtering material.
One feature of the present invention resides in the provision of a method of making a series of successive elongated rod-shaped smokable articles wherein longitudinally extending central core portions are surrounded by tube portions which, in turn, are surrounded by tubular wrapper portions. The improved method comprises the steps of forming a continuous elongated core component of a first material and advancing the core component lengthwise in a predetermined direction along a predetermined path, and building a continuous tube component of a second material around successive increments of the advancing core component in at least one first portion of the path (the building step can be carried out in several successive stages) to thus provide a composite rod-shaped filler wherein the tube component surrounds the core component. At least one of the forming and building steps includes providing the respective component with alternating first and second sections respectively containing larger and smaller quantities of the respective material, and the method further comprises the steps of draping successive increments of the filler into a continuous web of wrapping material in a second portion of the path downstream of the at least one first portion, and repeatedly severing the draped filler at the first sections to thus convert the draped filler into the aforementioned series of rod-shaped smokable articles each having a first end and a second end. This ensures that at least one end of each article contains the larger quantity of the respective material. If the draped filler is severed across the first sections, each end of each article contains a densified portion of the filler. Densification takes place as a result of draping of the filler, e.g., in a mechanism similar to that utilized in cigarette rod making machines wherein a continuous rod-shaped filler of tobacco is confined in a web of cigarette paper.
The articles which are obtained in response to repeated severing of the draped filler can be of unit length (i.e., each such article can constitute a plain cigarette, cigar, cigarillo or the like) or of multiple unit length (such articles are often utilized in filter tipping machines wherein plain cigarettes or the like are joined with filter rod sections to form therewith filter cigarettes or the like. As a rule, the articles which are obtained as a result of severing of the draped filler have identical lengths.
Each of the folding and building steps can include providing the respective component with alternating first and second sections which respectively contain larger and smaller quantities of the respective material. This can result in the making of rod-shaped articles having ends containing tightly packed particles of first and second materials. Alternatively, it is possible to achieve savings in the first and/or second material by reducing the quantities of first material in the first portions of the core component and/or the quantities of second material in the first portions of the tube component. The forming and building steps of a method wherein each of the forming and building steps includes providing the respective component with alternating first and second sections can further comprise distributing at least the first sections of the core and tube components at predetermined distances from each other (as seen in the longitudinal direction of the draped filler).
Still further, the just discussed method can further comprise the steps of monitoring the positions of the first sections of at least one of the core and tube components in a third portion of the path downstream of one of the first and second path portions, and correcting the positions of the first sections in the core component and/or in the tube component when the monitored positions deviate or depart from predetermined (e.g., experimentally ascertained optimum) positions. In accordance with such method, the aforementioned correcting step can be carried out when the monitored positions deviate from the predetermined positions to a predetermined extent, i.e., an extent outside of an acceptable range.
The aforementioned monitoring and correcting steps can be carried out with equal advantage if only one of the two components is provided with alternating first and second sections.
The method can further comprise the steps of measuring the density of the draped filler, utilizing the measuring step to ascertain the length of the first sections in the predetermined direction, comparing the ascertained length of the first sections with a predetermined (standard) length, and correcting the at least one of the forming and building steps when the comparing step reveals departures of ascertained length of the first sections from the predetermined length. The correcting step can include changing the length of the first sections to the predetermined length.
Alternatively, the improved method can comprise the additional steps of measuring the density of the draped filler in a further portion of the path at a fixed distance from a stationary reference point at the path, utilizing the results of such measurements to ascertain the distances of successive first sections from the reference point and the lengths of successive first sections in the predetermined direction, and adjusting the at least one of the forming and building steps when the lengths of successive first sections depart from a preselected value. The severing step of such method is or can be carried out at the stationary reference point.
If each of the forming and building steps includes providing the respective component with alternating first and second sections respectively containing larger and smaller quantities of the respective material, the severing step can be carried out in a third portion of the path downstream of the second portion. One of the forming and building steps in such method can include providing the respective component with first sections at a fixed distance from each other (as seen in the predetermined direction), and the other of the forming and building steps can include providing the respective component with first sections at a variable distance from each other (as seen in the predetermined direction) Still further, if each of the forming and building steps includes providing the respective component with alternating first and second sections respectively containing larger and smaller quantities of the respective material, the method can further comprise the steps of monitoring the density of the core component upstream of the first portion of the path to thus ascertain the distances of successive first sections of the core component from a fixed reference point at the path, comparing the thus ascertained distance with a predetermined distance, and correcting the positions of the first sections of the core component relative to the first sections of the tube component in the predetermined direction when the ascertained distances depart from the predetermined distance.
The method can further comprise the steps of establishing an elongated reservoir in a preselected portion of the path upstream of the at least one first portion of the path, and monitoring the density of the core component at a portion of the reservoir nearest to the at least one first portion of the path.
If each of the forming and building steps includes providing the respective component with alternating first and second sections respectively containing larger and small or smaller quantities of the respective material, the method can further comprise the steps of monitoring, in a further portion of the path, the distances of successive first sections in one of the components from a fixed reference point at the path, comparing the monitored distances with a reference distance, and at least temporarily adjusting the forming or the adjusting step when the comparing step reveals a departure of the monitored distances from the fixed reference distance.
Another feature of the present invention resides in the provision of an apparatus for making a series of successive elongated rod-shaped smokable articles wherein longitudinally extending central core portions are surrounded by tube portions which, in turn, are surrounded by tubular wrapper portions. The improved apparatus comprises means for forming a continuous core component of a first material including means for advancing the core component lengthwise in a predetermined direction along a predetermined path, and means for building a continuous tube component of a second material around successive increments of the advancing core component in at least one first portion of the path to thus provide a composite rod-shaped filler wherein the core component is surrounded by and advances with the tube component. At least one of the forming and building means includes at least one densifying means for providing the respective component with alternating first and second sections respectively containing larger and smaller quantities of the respective material, and the apparatus further comprises means for draping successive increments of the filler into a continuous web of wrapping material in a second portion of the path downstream of the at least one first portion, and means for repeatedly severing the draped filler at the first sections of the core component and/or the tube component to thus convert the filler into the aforementioned series of articles each having a first end and a second end. At least one end of each article contains the larger quantity of the respective material.
The advancing means of the core forming means includes means for transporting the core component, the tube component and he draped filler at a predetermined speed, and the severing means includes means for cutting across the draped filler in the predetermined path at a frequency in synchronism with the predetermined speed so that the series of successive elongated rod-shaped smokable articles contains articles having a predetermined length, namely unit length or multiple unit length.
It is often preferred to construct the improved apparatus in such a way that each of the core forming means and the tube building means comprises at least one densifying means which is operable to provide the respective component with alternating first and second sections respectively containing larger and smaller quantities of the respective material. Such apparatus can further comprise means for synchronizing the operation of the at least one densifying means of the core forming means with the operation of the at least one densifying means of the tube building means.
As a rule, the densifying means is adjustable, and the apparatus employing one or more adjustable densifying means further comprises means for monitoring the component turned out by the (forming or building) means including an adjustable densifying means. The monitoring means is designed to generate signals in response to detection of the first sections, and such apparatus further comprises means for evaluating the signals and for initiating adjustments of the densifying means when the positions of the first sections relative to a predetermined reference point deviate from predetermined positions. The adjustments preferably involve at least partial elimination of deviation of monitored positions of the first sections in the core component and/or in the tube component from the predetermined positions.
If each of the forming and building means comprises at least one densifying means and at least one of the densifying means is adjustable, the apparatus can further comprise first and second means for respectively monitoring the core component and the tube component and for generating first and second signals in response to detection of the respective first sections. Such apparatus can further comprise means for evaluating the signals and for initiating adjustments of the at least one adjustable densifying means when the positions of detected first sections provided by the at least one adjustable densifying means depart from predetermined positions. The evaluating means is operative to effect adjustments of the first sections provided by the at least one adjustable densifying means in a sense to at least reduce departures of positions of detected first sections from the predetermined positions.
The severing means is spaced apart and can be disposed at a predetermined distance from the at least one densifying means, and the densifying means of such apparatus can comprise means for providing or turning out the first sections at a first frequency which is a function of the speed of lengthwise advancement of the core component along the predetermined path. The severing means can comprise means for cutting across the draped filler at a second frequency in synchronism with the first frequency to thus ensure that each article comprises a first section at the at least one end of such article.
If each of the forming and building means comprises at least one densifying means and if at least the at least one densifying means of the forming means is adjustable, the apparatus can further comprise first signal generating means for monitoring the core component in a third portion of the predetermined path upstream of the at least one first portion to ascertain the positions of first sections of the core component, second signal generating means for monitoring the tube component to ascertain the positions of first portions of the tube component, and means for evaluating signals from the first and second signal gene-rating means and for adjusting the at least one adjustable densifying means when the monitored positions of first sections of the core component relative to the monitored positions of first sections of the tube component depart from predetermined values.
The apparatus can further comprise a reservoir for a length of advancing core component between the forming means and the building means. Such reservoir has an intake end nearer to and a discharge end remote from the forming means, and such apparatus further comprises signal generating means for monitoring the densities of successive increments of the core component and the positions of successive first sections of the core component relative to a fixed reference point. The path for the core component in such apparatus includes a portion which is disposed between the intake and discharge ends of the reservoir and wherein the core component is free to sag under the action of gravity. The advancing means of the forming means in such apparatus is adjustable by a position monitoring device which serves to vary the speed of the core component as a function of changes of the extent of sag of the aforementioned portion of the core component in the reservoir.
The advancing means can comprise an endless foraminous belt or band conveyor, a suction chamber adjacent one side of the conveyor, and means for delivering successive increments of the core component toward the other side of the conveyor. The means for building a continuous tube component comprises means for establishing a layer of the second material at the other side of the conveyor prior to delivery of successive increments of the core component so that the delivered increments of the core component overlie the layer.
As a rule, or at least in many instances, at least one of the first and second materials is a particulate material, e.g., tobacco shreds. The at least one densifying means can comprise at least one equalizing device having means for converting an untrimmed flow of particulate material into a trimmed flow wherein the first sections alternate with the second sections as seen in the predetermined direction. Such trimming or equalizing devices are utilized extensively in cigarette rod making machines to convert a stream of tobacco particles into a rod-like filler ready to be draped into a continuous web of cigarette paper.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of making, assembling and operating the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawings.